Brake squeak

[oyster]

The other day I replaced my front brake pads. (They are just common Shimano hydraulic disc brakes.) Reason - they were squeaking. I actually thought they must have been down to the metal. They certainly were worn but a reasonable layer was left. With my rear brakes, when they started squeaking and not being as effective, they really were worn and you could just about see the metal.

Now replaced, the front brakes are back to being nice and quiet, as they always were until very recently.

What is that actual cause of brake squeak?

 

[soundwave]

the pads and the rotors are contaminated clean the rotor and pads with isopropyl alcohol then sand both with some fine sand paper if they still squeak then you need new brake pads.

 

[JPGiant]

+1 for soundwave, also, ensure the caliper bolts are loose, pull the brakes ON then tighten caliper bolts.

 

[oyster]

the pads and the rotors are contaminated clean the rotor and pads with isopropyl alcohol then sand both with some fine sand paper if they still squeak then you need new brake pads.

Thanks. Had already cleaned the discs with isopranol - little, if any, change.

The new pads have made them as quiet as ever they were. Though perhaps I should have done so, I didn't put much effort into cleaning anything as I re-assembled.

 

[oyster]

+1 for soundwave, also, ensure the caliper bolts are loose, pull the brakes ON then tighten caliper bolts.

Thanks. With the new pads, that is exactly what I did.

 

[soundwave]

when you change the pads you should also clean and lube the inside of the brake caliper and lube the pistons as grime will build up over time and get sticky pistons.

https://www.ebay.co.uk/itm/Hope-HTTLUBE-Silicon-Lube-Brake-Grease-30ml/162301127415?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649